Three review: Bought an iphone 14 pro max from Three

I had bought an Iphone 14 pro max from hanley stoke on trent Three store on January 2023 with the Sim number [protected].

I am a student here.

I was actually paying 86 pounds per month for the phone and suddenly after some months the rate has increased and when i spoke to them,they were saying thats because of the CPI or something which i didnt even know.

Till now i have paid almost 750 pounds to three and when i talk to them about to close my contract by finish of by paying the remaining amount they are saying that i need to pay 1500 or something again.They are saying that i have taken 30 gb unlimited data contract and for that reason the contract expires on january 2025 and i need to pay the 86 pounds till that time.That means i need to pay 16 months more.And when i told them to cancel that contract they are saying that they cant cancel the contract.i am really in trouble now.i am a student here and i cant afford this.The phone is only 1350 and almost i paid 750 for this.they are saying because of the contract i taken i need to pay 16 months more this 86 pounds.Howz this possible?Kindly please help me to get rid of this issue

Thanks

Nobin